1. Field of the Invention
The present invention relates to a liquid crystal display (LCD) and method of fabricating the same and, more particularly, to an LCD having a patterned opposing common electrode including apertures and method of fabricating the same.
2. Description of the Related Art
An LCD has a liquid crystal injected between a pixel electrode and an opposing common electrode, and changes alignment of the liquid crystal by applying an electric field between the pixel electrode and the opposing common electrode. The changed alignment of the liquid crystal controls transmittance of light to form images.
Among various types of LCDs, an optical controlled birefringence (OCB) type LCD has a fast response speed and an excellent viewing angle. The OCB type LCD includes a pixel electrode, a bottom alignment layer, an opposing common electrode, a top alignment layer, and a liquid crystal layer with nematic liquid crystals having positive dielectric constant anisotropy Δε. The bottom and top alignment layers are rubbed in the same direction, so that the liquid crystals have a splay alignment. In order to form images in the OCB type LCD, a high electric field should be formed between the pixel electrode and the opposing common electrode. The high electric field changes a tilt angle of the liquid crystals located at a center of the liquid crystal layer to an angle of 90° so that the liquid crystals have a bend alignment. This is referred to as a bend transition. A predetermined voltage is applied between the pixel electrode and the opposing common electrode to induce change of a tilt angle of the rest of the liquid crystals other than the liquid crystals adjacent to the alignment layers and the liquid crystals located at the center. Thus, polarization of light which passes through the liquid crystal layer is changed to form the images.
In order for the LCD having a plurality of pixels to realize high resolution images, most of the liquid crystals arranged in the plurality of pixels should be bend-transitioned. However, this requires a lengthy time, and pixels which are not bend-transitioned may occur. In order to prevent this, a voltage is increased for the bend transition, leading to high power consumption.
In order to solve the problem, Japanese Publication No. 2003-140194 discloses an LCD with a pixel electrode having a groove portion or a protruding portion. However, it may reduce an aperture ratio to form the groove portion or the protruding portion in the pixel electrode.
Discussions on OCB type LCDs are found in the following references, incorporated by reference: U.S. Pat. No. 6,600,540 to Hiroyuki Yamakita et al. and titled LIQUID CRYSTAL DISPLAY discusses a liquid crystal display comprising a pair of opposed substrates, a liquid crystal layer disposed between the pair of substrates, a storage capacitor electrodes provided on one of the pair of substrates, and pixel electrodes provided so as to overlap with the storage capacitor electrodes, the pixel electrode having an aperture in a region overlapping with the storage capacitor electrode; U.S. Pat. No. 6,714,276 to Michael John Towler et al. and titled LIQUID CRYSTAL DISPLAY DEVICE discusses a reflective liquid crystal display comprising a pair of opposed substrates, a liquid crystal layer disposed between the pair of substrates, transparent electrodes and reflective electrodes provided with via-hole regions functioning as a nucleation regions; and U.S. Pat. No. 6,852,374 to Masanobu Mizusaki et al. and titled LIQUID CRYSTAL DISPLAY DEVICE, OPTICAL ELEMENT, METHOD OF FABRICATING THE LIQUID CRYSTAL DISPLAY DEVICE AND METHOD OF MAKING THE OPTICAL ELEMENT which discusses a liquid crystal display device (LCD), an optical element, a method of fabricating the LCD and a method of making the optical element, and also relates to a material of a liquid crystal alignment film that can be used effectively in the LCD or the optical element.